crayfish – Field Station /field-station/tag/crayfish/ UW-Milwaukee Thu, 11 Jul 2024 15:39:30 +0000 en-US hourly 1 https://wordpress.org/?v=6.9.4 Stirrings of Summer /field-station/bug-of-the-week/stirrings-of-summer/ Thu, 11 Jul 2024 15:39:28 +0000 /field-station/?p=15057 Greetings, BugFans Here are some of the bugs that the BugLady found in June, which was, overall, a hot and wet month (7.97” of rain at the BugLady’s cottage). Lizzard Beetle – the BugLady doesn’t know why these striking beetles …

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Greetings, BugFans

Here are some of the bugs that the BugLady found in June, which was, overall, a hot and wet month (7.97” of rain at the BugLady’s cottage).

lizard on a stem

Lizzard Beetle – the BugLady doesn’t know why these striking beetles are called Lizard beetles, unless it’s a nod to their long, slender shapes.She usually sees them in the prairie on Indian Plantain plants.The adults eat various parts of the plant, including pollen, while their larvae feed within the plant stems (the Clover stem borer is persona non grata in commercial clover fields).

According to the Encyclopaedia Britannica, many species of Lizard beetles “make squeaking sounds using well-developed stridulatory organs on top of the head.

bug on the pond

Two (counterintuitively-named) Orange Bluets, ensuring the next generation.He “contact guards” her as she oviposits in submerged vegetation, lest a rival male come along and swipe her.When the eggs hatch, the naiads can swim right out into the water.

butterfly on a flower

Baltimore Checkerspot – the BugLady has seen more of these spectacular butterflies than usual this year.The  feed in fall on a late-blooming wildflower called Turtlehead (and sometimes broad-leaved plantain); turtlehead leaves (and plantain, to a lesser extent) contain growth-enhancing chemicals called iridoid glycosides that also discourage birds. The caterpillars tuck in for the winter and emerge the next year into a landscape empty of Turtlehead.

In spring, Baltimore Checkerspot caterpillars 2.0 feed on leaves of a variety of flowers and shrubs – the BugLady has seen them on goldenrod and on wood betony – and especially on leaves of the (doomed) white ash. 

crayfish on the ground

Crayfish – the BugLady came across this crayfish and its companion when all three of us were negotiating a muddy trail (so many muddy trails this year!). It waved its pincers at her to make sure she was terrified.

bugs on the ground

Doodlebugs (aka antlions) got going early this year – the BugLady found more than 100 excavations (pits) at the southeast corner of her house at the end of April, and more along the path leading to the beach.They’ve had a rough go of it – it doesn’t take much rain to ruin a pit, and it takes a day or so to repair one. 

Doodlebug watchers sometimes catch a glimpse of pincers at the bottom of a pit, or of a doodlebug tossing sand around.The BugLady witnessed an ant going to its final reward, and found a pit with a small beetle in it, one with a box elder bug, and one with a beetle and a small jumping spider.She will look for the adults, which look kind of like damselflies, in August.

moth on the wall

Donacia – a  on a golden flower.

beetle inside a flower

Common Spring Moth – the BugLady loves finding bugs she’s never seen before, especially when she doesn’t have to leave home to do it!! (She does get a little bewildered, though, when the “new” insect is named the “Common something” and she’s never seen it before).The occurrence of this one should be no surprise – its caterpillars feed on Black locust leaves.

Group of moths on flowers

Petrophilia Moths are dainty moths that are tied to water.The BugLady and BugFan Joan spotted mobs of moths on milkweed (yes, there’s a milkweed under there) on the bank of the Milwaukee River. “Petrophila” means “rock lover” – for that story, read the BOTW about a (probably) different species.  

bug eggs on a stem

Green Lacewing Eggs – the BugLady wrote about Green lacewings and their eggs a few months ago, and she recently found this amazing bunch of tiny, glistening eggs.She has always associated Green lacewings with the end of summer.Guess not.

moth on a leaf

Eight-Spotted Forester Moths are small, spiffy, day-flying moths that are often mistaken for butterflies. The one that the BugLady found recently was not as gaudy as most – most have brilliant .There’s a saying among Lepidopterists – the plainer the caterpillar, the more spectacular the adult..

bug on a leaf

Powdered Dancers oviposit at this time of year in the slightly-submerged stems of aquatic vegetation, especially .They’ve been pictured here before.This year, the river is running high and fast – there are no mats of Potamogeton leaves with Ebony Jewelwings, American Rubyspots, Stream Bluets, and Powdered Dancers flickering above them.Do they have a Plan B?

male spider on a leaf
female spider on flower

These two Brilliant Jumping Spiders (aka Red & Black jumping spiders), a male and a female, were perched a respectful distance from each other on the prairie.Jumping spiders, as their name suggests, jump, and depending on species, can cover from 10 to 50 times their body length.They don’t spin trap webs, but they do spin a drag line while jumping to guard against mishaps.They hunt by day.

The great MObugs website (Missouri’s Majority) says that “By late July or August mating is on their mind. Males begin to compete with other males for the right to mate with nearby females. Larger males typically win these competitions which include loud vibrations and some unique footwork. Males choose the larger females to mate with as they produce the most eggs.” She will place her egg sac in a silken nest in a leaf shelter and guard it, dying shortly after the spiderlings emerge from the sac.

bug on a leaf

Zelus Luridus (aka the Pale green assassin bug) is the BugLady’s favorite Assassin bug.They mostly wait patiently for their prey to wander by, but when it does, they reveal their super power. Glands on their legs produce a sticky resin that they smear over the hairs on their legs. When they grab their prey, it stays grabbed.

They make  (nice series of shots) – the BugLady has found them on the undersides of leaves, and the are pretty cool, too.

Although “lurid” now means shocking, vivid, or overly bright, it originally meant ghastly, horrifying, pale, sallow, or sickly yellow – its meaning began to change in the 1700’s.  

There – all caught up! 

Go outside – look at bugs!

The BugLady

(Just before this episode was launched,  was inexplicably offline – if it still is, check the links later)

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Crayfish Revisited /field-station/bug-of-the-week/crayfish-revisited/ Wed, 23 May 2018 20:40:27 +0000 /field-station/?p=9413 Still in the process of moving, and it’s May, so another re-run. The BugLady dusted off another decade-old episode (yes, BugFan Laurel – 10 years!!!) and added new pictures and information. And yes, as always, the BugLady is using a rather inclusive definition of the word “bug.”

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Greetings, BugFans,

Still in the process of moving, and it’s May, so another re-run. The BugLady dusted off another decade-old episode (yes, BugFan Laurel – 10 years!!!) and added new pictures and information. And yes, as always, the BugLady is using a rather inclusive definition of the word “bug.”

Crayfish are classified in the Phylum Arthropoda (“jointed legs”), in the Class Crustacea (referring to their hard, outer coverings), and in the Order Decapoda (“ten legs”). More than 300 species of these “mini-lobsters” blanket North America; the Rocky Mountains and western Great Plains have historically been fairly crayfish-lite, and the Southeast is most species-rich. A Wisconsin DNR publication dated 2012 lists eight species in the state at that time—Northern Clearwater, Rusty, and Virile crayfish (the three most common species), and Devil, Calico, White River, Red swamp, and Prairie crayfish.

Crayfish
Crayfish inhabit shallow waters, running and still, though some live in damp-lands away from standing water, and some will even settle at the base of a hillside where run-off from above provides their moisture. Most species are intolerant of pollution. Species that live in drier conditions or whose aquatic homes dry up in late summer build “chimneys” in an attempt at climate-control. In search of water to keep their gills moistened, these relative landlubbers excavate vertical tunnels in the earth, constructing at the mouth of the tunnel a cylindrical pile of mud pellets—a chimney. There they live, in damp and solitary splendor (except for a bit of co-habiting during the breeding season). The Bug Lady’s youngest child once wrote in a poem that “crayfish build chimneys so their voices will echo when they sing.”
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According to Wikipedia, “The study of crayfish is called astacology.”

A carapace covers the cephalothorax (fused head and thorax), and the “snout” that protrudes from the front of the carapace is called the “rostrum.” Antennae and stalked eyes decorate the cephalothorax, and five pairs of walking legs are found on its underside (the front set has been modified into a pair of impressive claws that they use to crush or rip their food). Gills and a balance organ, into which the crayfish incorporates grains of sand as sensors, are located inside it.
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The abdomen consists of six segments terminating in a flipper-like “telson” (tail). Below the first five segments are pairs of small appendages called swimmerets. The swimmerets move to create water currents that wash over the gills and assist in respiration, and they also function in reproduction. Crayfish go forward by creeping and move backward pretty fast by tucking/folding their jointed abdomen under them several times, and they can walk sideways. If a limb is lost, a crayfish can regenerate it.


 for an up-close look at the external anatomy of a crayfish.

Crayfish (crawfish, crawdads, mudbugs) are omnivores and often scavengers, feeding on dead plants, live plants, snails (mainly those species with thinner shells), aquatic insects, small fish and carrion (when she was in a much earlier instar, the Bug Lady was given some raw bacon with which to angle for crayfish, and both she and the crayfish thought it was mighty tasty). Crayfish are eaten by raccoons, otters, screech owls, lots of fish (and, apparently, Ring-billed Gulls), and by humans, who should cook them well in order to avoid a lung fluke that some crayfish are intermediate hosts of in the eastern part of their range.

J. Reese Voshell, Jr, in his excellent book “A Guide to Common Freshwater Invertebrates of North America,” tells us that crayfish are an important domino in aquatic ecosystems. Their actions may determine the density of the aquatic plants, which determines the health and composition of the accompanying animal community.

Invasive crayfish? Two of Wisconsin’s species are.

The aggressive Rusty crayfish (Orconectes rusticus), is an invasive “native” (native, that is, to the Ohio River Basin) that was first found in Wisconsin in 1960 and has since achieved pest status here. Rusty crayfish were probably introduced by bait fishermen and/or aquarium owners discarding unwanted animals into ponds and waterways, but they are also sold to schools by biological supply companies, and when the kids go home for the summer… They are aggressive toward native crayfish, toward the fish that would normally eat them, and toward the toes of wading humans. They eat twice as much as native crayfish, and they impact fish populations by eating fish eggs, small fish, insects eaten by fish, and aquatic vegetation needed by fish for cover and for spawning areas. And they reproduce avidly. Pretty much a clean sweep, damage-wise.

; for an interesting tale of crayfish eradication, . Rusty crayfish control?

Since this original crayfish episode was written 10 years ago, a second alien crayfish has appeared in Wisconsin, the Red swamp crayfish (Procambarus clarkii). Back in the summer of 2009, residents of a subdivision northwest of Milwaukee started finding bright red crayfish in their lawns (and running them over with lawnmowers). . This species is farmed extensively in the south and shipped live to people who want to have a real Cajun crawfish boil, and it’s also sold as a classroom animal – whatever the origin, someone released the extras.

Red swamp crayfish are called an “ecologically plastic species,” another way of saying that they’re very adaptable. They tolerate drought and can hike considerable distances looking for water. Like the Rusty crayfish, they out-compete and out-reproduce the native species, and they are notably hard on amphibians. Red swamp crayfish can transmit to native crayfish a fungal disease called “crayfish plague,” which damages the muscles. On their home turf around the Gulf Coast, this crayfish is famous for weakening earthen berms and undermining stream banks with its tunnels.

. They’ve also immigrated to more than 25 European and Asian countries.

Yay – dandelions are blooming!!!

The BugLady

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